Carver amp buzzing noise

[tonionc]

Happy New Year! It's been a while since I have posted and want to thank everyone again for all the great information.

I recently purchased a used Carver m4.0t amp and C-1 preamp. I was very happy with this equipment but after about a month, I noticed that the amp was making a louder humming noise or buzz. This soon became very annoying and I could hear it increasing in speaker hiss and buzz. Well, I actually did not know it was the amp until I isolated every other component and the amp was the only thing making this noise, I also hooked up a friend's amp to test and everything was fine.

So, my question is what could be going wrong in the m4.0t amp and what do you think this might cost to repair? Is it worth repairing? Is this amp something that a good audio store could work on or does it need to be sent to an authorized carver repair place?

In the future, what do you recommend as far as connecting the amp to an outlet? Any special kind of power surge protector should be used? Thanks in advance for any advice on this. I was quite happy with this Carver amp and preamp and have no idea what this kind of repair might entail.

Thanks,

Antonio

[Kevio]

Is the buzz coming directly from the amplifier or is it coming out of the speakers?

If the former, there's something gone bad with the transformer and should be easy to diagnose and repair (though not necessarily cheap) possibly by replacing the main power transformer.

If the latter something is bad in the amplifier or power supply circuits. This can be harder to diagnose. I had an amp that did this and it turned out to be a dirty ground connection on the circuit board - took several attempts to find and fix.

If the amp is still under warranty, you'll definitely want to contact Carver and discuss repair/replacement procedure.